The Chilgog Formation (Korean: 칠곡층; Hanja: 漆谷層; RR: Chilgok-cheung), also known as the Chilgok Formation, is an Early Cretaceous geologic formation in South Korea. Formerly dated to the Berriasian to Hauterivian, later dating has established an Albian age. Dinosaur remains, possibly of sauropods, are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.

The formation predominantly consists of sandstone, mudstone and conglomerate, with subordinate tuff and other volcanics. It overlies the Jinju Formation and underlies the Silla Conglomerate, which underlies the Haman Formation, respectively.

• ko:경상 분지 (Gyeongsang Basin)
• List of dinosaur-bearing rock formations
  • List of stratigraphic units with indeterminate dinosaur fossils

• Lee, Tae-Ho; Park, Kye-Hun; Yi, Keewook (2018), "Nature and evolution of the Cretaceous basins in the eastern margin of Eurasia: A case study of the Gyeongsang Basin, SE Korea", Journal of Asian Earth Sciences, 166: 19–31, Bibcode:2018JAESc.166...19L, doi:10.1016/j.jseaes.2018.07.004
• Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2, retrieved 2019-02-21
• Choo, Chang Oh; Shin, Young Sik; Koh, In Seok (2002), "Mineralogical evidence for red coloration of sandstones at the Chilgok Formation of the Cretaceous Hayang Group, Southeastern Korea", Geosciences Journal, 6 (2): 141–148, Bibcode:2002GescJ...6..141C, doi:10.1007/BF03028285, ISSN 1226-4806
• Kim, H.M (1981), "Cretaceous dinosaur bones excavated from two localities in Korea", Journal of the Geological Society of Korea, 17: 297